CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-92697
High (7.5) in pavel-odintsov fastnetmon. EPSS 1.1% estimated probability of exploitation activity in the next 30 days.
On this page
FastNetMon is a high-performance DDoS detector and sensor. In version 1.2.9 and earlier, the NetFlow v9 collector calls strlen() on an attacker-controlled interface-description field without bounding the scan to the field’s declared length. Although fields longer than 128 bytes are excluded from this operation, an accepted field without a null terminator can cause reads beyond the field and packet buffer. An unauthenticated remote attacker who can send crafted UDP packets to the collector can trigger an out-of-bounds read and potentially crash the process, causing denial of service. No fixed release is available as of this review.
Severity
- EPSS
- 1.1% estimated probability of exploitation activity in the next 30 days; 67th percentile. Scored 2026-11-10. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: PoC · Automatable: yes · Technical impact: partial, assessed 2026-11-10. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-125 Out-of-bounds Read
- Published
- Modified
- Assigned by
- GitHub_M (CNA)
- NVD analysis
- Deferred: the NVD does not plan to analyze it
- Record from
- the NVD, synced
Ask an AI about this CVE
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Explain CVE-2026-92697 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-92697?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-92697?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-92697 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| pavel-odintsov fastnetmon | <= 1.2.9 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12, 13, 14 | fastnetmon | no fix listed | DEBIAN-CVE-2026-92697 |
| Ubuntu | 18.04:LTS, 26.10, Pro:20.04:LTS and 2 more | fastnetmon | no fix listed | UBUNTU-CVE-2026-92697 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu.
Red Hat
Red Hat rates this Important.
Red Hat rates this vulnerability as Important because an unauthenticated remote attacker can abruptly terminate the monitoring daemon without credentials, leading to a complete service disruption. This risk warrants an Important severity rating because disabling the network sensor blinds administrators to traffic anomalies and denial-of-service conditions, despite the flaw not facilitating code execution or data exposure. Impact is greatest in environments where the NetFlow collector port is exposed to wider network segments rather than restricted to authorized flow-exporting devices.
Restrict network exposure so only trusted network devices (such as designated flow-exporting routers and switches) can reach the NetFlow collector port, or disable the daemon if flow monitoring is not needed.
1. Restrict the NetFlow UDP port (default 2055) to trusted sources using firewalld:
```
firewall-cmd --permanent --zone=trusted --add-source=<ROUTER_IP>/32
firewall-cmd --permanent --zone=trusted --add-port=2055/udp
firewall-cmd --reload
```
2. Alternatively, disable the service entirely if NetFlow processing is not required:
```
systemctl stop fastnetmon
systemctl disable fastnetmon
```
Caveats:
Restricting UDP traffic mitigates untrusted external exploitation, but any flow exporter within the allowed IP range could still trigger the flaw if compromised or misconfigured. Stopping the daemon halts DDoS traffic detection and flow collection completely.
Warning: Modifying firewall rules requires reloading the firewalld configuration (`firewall-cmd --reload`), which immediately alters active packet filtering rules. Stopping the daemon interrupts active monitoring services.
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-92697.
Attack patterns (CAPEC)
- CAPEC-540 Overread Buffers Likelihood: Low · Severity: High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.